Reversible refrigeration system



Dec. 4, 1962 c. A DUBBERLEY REVERSIBLE REFRIGERATION SYSTEM Filed June 21. 1961 603 2 9 7! m NM INVENTOR. CHARLES A DUBBERLEY BY ,fiz/ylw g H\S ATTORNEY 3,066,497 REVERSIBLE REFRIGERATION SYSTEM (Iharles A. Dubberley, Tyler, Tex., assignor to General 7 Electric Company, a corporation of New York Filed June 21, 19611, Ser. No. 118,725 3 Claims. (Cl. 62-499) The present invention relates to and has for its principal object the provision of a reversible refrigeration apparatus of the type used for heating and cooling purposes and incorporating improved servicing features.

In accordance with the present invention there is provided a reversible refrigeration apparatus for heating or cooling an enclosure, which includes a compressor and first and second heat exchangers. The heat exchangers are connected by a liquid refrigerant line or conduit including expansion means designed to expand refrigerant from condenser pressure to evaporator pressure during flow through the conduit in either direction. Suction and discharge tubes connect the compressor to a reversing valve which may be operated to selectively direct discharge gas into either of the heat exchangers and to direct suction gas flowing from either of the heat. exchangers into the compressor. Refrigerant lines connect the reversing valve with the heat exchangers and, in order to provide improved servicing of the reversing valve and its associated compressor, the refrigerant lines are provided with service valves which are detachably coupled to the reversing valve. Manually operable valve means in the service valves are provided for sealing the refrigerant lines thereby permitting removal of the refrigerant lines from the reversing valve without loss of refrigerant charge in these lines and the heat exchangers during servicing of the compressor or the reversing valve.

For a better understanding of the invention, reference may be had to the accompanying drawing, the single FIGURE of which shows, in somewhat schematic form, a reversible refrigeration system of the type employed for heating or cooling an enclosure which incorporates the improved servicing arrangement of the present invention.

Referring now to the drawing, it will be seen that the illustrated reversible refrigeration system includes an indoor heat exchange and air handling unit, designated generally by the reference numeral 2, and an outdoor heat exchange and refrigerating machine unit, designated by the reference numeral 3. The outdoor unit 3 includes a first or outdoor heat exchanger 6 and the indoor unit 2 includes a second or indoor heat exchanger 4. A liquid refrigerant line or conduit 5 is connected between the indoor and outdoor heat exchangers 4 and 6 and conducts refrigerant between these heat exchangers. Refrigerant expansion means are provided in the refrigerant line 5 for expanding refrigerant from condenser pressure to evaporator pressure during refrigerant flow through the line 5 in either direction. More specifically the expansion means may include a pair of thermally responsive valves or, as shown in the drawing, a pair of capillaries 7 and 8, hereinafter referred to as the outdoor capillary 7 and the indoor capillary 8, which control the expansion of refrigerant during the respective heating and cooling cycle operations of the system. As will be seen in the drawing, a bypass line 9 is provided for bypassing refrigerant around the capillary 7 when refrigerant is flowing from the heat exchanger 6 toward the flow control means or capillary 7, or when the heat exchanger 6 is operated as a condenser. However, when refrigerant is flowing from the indoor unit 2 in the direction toward the heat exchanger 6, a check valve 10 closes the bypass 9 and forces all of the refrigerant through the capillary 7. The capillary 7 then expands the refrigerant from condenser pressure to evaporator pressure and the heat exchanger '6 then operates as an evaporator. Also included in the bypass line 9 is a filter drain 20 which removes any moisture in the system and filters the refrigerant during flow on the cooling cycle.

A bypass conduit 11 is provided for' diverting refrigerant flow around the indoor capillary 8, connected in series with the heat exchanger 4, when the heat pump is operating on the heating cycle or, more specifically, when the refrigerant flow is from the indoor heat exchanger 4 toward the capillary 8. However when refrigerant is flowing in the opposite direction, or during the cooling cycle operation of the system a check valve 12 prevents the flow of refrigerant through the bypass 11 and the capillary 8 then expands the liquid refrigerant flowing toward the indoor heat exchanger 4 from condenser pressure to evaporator pressure. It should be mentioned that the capillary 8 is similar in operation to capillary 7 and that both capillaries 7 and 8 are sized to give optimum performance for the respective heating and cooling cycle operation. That is, capillary 8 provides the restriction for optimum performance of the refrigeration system under those conditions normally encountered during the cooling season and capillary 7 provides the necessary restriction to give optimum performance of the refrigeration system under those conditions normally encountered during the heating season.

The outdoor heat exchanger and refrigeration machine unit 3 also includes a compressor 13 having a discharge outlet (not shown) and a suction inlet (not shown) connected respectively to a suction conduit 16 and a discharge conduit 14 which, in turn, connect with a reversing valve or switch-over valve 17. The reversing valve 17 connects the suction line 16 and the discharge line 14 with the remaining portions of the refrigerant circuit so that the compressor withdraws refrigerant from either the outdoor heat exchanger 6 or from the indoor heat exchanger 4 and discharges refrigerant into the opposite of the two heat exchangers. More specifically, refrigerant lines 15 and 18 carry refrigerant between the reversing valve 17 and the outdoor and indoor heat exchangers respectively.

When the system is operating on the cooling cycle, compressed refrigerant from the compressor 13 is directed by the reversing valve 17 through the refrigerant line 15 toward the outdoor heat exchanger 6 in which the refrigerant is condensed. Liquid refrigerant flows from the outdoor heat exchanger 6 through the bypass line 9 and into the conduit 5 which connects with the door unit or indoor heat exchanger 4. Liquid refrigerant then flows through the indoor capillary 8 into the indoor heat exchanger 4 which functions as an evaporator. In the heat exchanger 4 the refrigerant is evaporated by absorbing heat'from an air stream circulated through the heat exchanger 4 from the dwelling or other structure being conditioned.

When the circuit is operated on the heating cycle, the compressed refrigerant from the compressor 13 is directed by the reversing valve 17 through the refrigerant line 18 connecting with the indoor unit or with the indoor heat exchanger 4 where the heat liberated during condensation heats the space being conditioned. The condensed refrigerant from the indoor heat exchanger 4 then fiows through the bypass 11 into the refrigerant line 5 leading to the outdoor unit 3 or outdoor heat exchanger 6. The refrigerant then passes through the capillary 7 and is expanded to evaporator pressure whereupon it enters the heat exchanger 6 which, on the heating cycle, functions as an evaporator.

The major moving parts of the above-described refrigeration system are found in the compressor 13 and in the switch-over or reversing valve 17. Consequently, it

3 is these components of the refrigeration system that are most likely to require servicing during the life of the refrigeration system. Therefore, the present invention incorporates an arrangement for easily servicing thesev valves 24 and 26 which in turn are connected by means of detachable couplings 27 and 28 to the reversing valve 17. That is, the outlets from the reversing valve .17 contain fittings such as the fitting 29 to which are detachably connected the service valves 24 and 26. A locking device holds the valve tightly onto the fitting 29'. In the illustrated arrangement the. valve is attached to the fitting 29 by means of a threaded locking nut 30 having shoulders 30a which engage with the valve spud 22 and tighten it down against the fitting 29. A gasket is normally employed between the fitting 29 and the valve spud 22 to provide a seal between the fitting 29 and the valve spud 22.

Manually operated valve means are provided in the service valves for sealing the refrigerant lines 15 and 18 ,leading to the heat exchangers.

More specifically, as may be seen by reference to valve 26, a valve stem 31 having an axially movable valve member 32 is provided within the valve body 26 which may be manually operated by means of the rotatable handle 33 to engage or disengage from the valve seat 34 leadi: g to the refrigerant line 18. It will be understood that valve member 24 operates similarly to valve 26 and the rotatable handle 33a may be adjusted to open or seal the refrigerant line 15.

It will also be noted that the discharge tube 14 and the suction tube 16 are connected to the compressor 13 by means of detachable couplings 35 and 36 which are similar to the couplings attaching the service valves 24 and 26 to thereversing valve 17. More specifically, referring to the coupling 35, a fitting or spud 29a is attached to the discharge outlet of the compressor whereby the discharge tube 14 is attached in the refrigerant sealed relationship with the fitting 29a by means of the locking nut 30. A spud 22a, similar to spud 22 on service valve 26, is attached to the end of tube 14 thereby providingmeans on the end of the tube 14 which may be sealed by the shoulders of the locking nut 30 against the face of the fitting 29a. It will be understood that the suction line 16 is also attached to the suction inlet of the compressor 13 in a similar manner.

In order to further facilitate the servicing operation of the above-described refrigeration system, a liquid line service valve 41 is provided in the refrigerant line 5 which may be manually operated in the same manner as valves 24 and 26 to close the refrigerant line 5. The valve 41 is more accessible if placed adjacent the outdoor unit 3 and is shown in that position in the drawing. It will be understood however, that it could be placed more closely to the indoor unit 2, if desirable.

The above described service valve arrangement promotes ease of servicing operations and permits removal of the reversing valve 17 or the'compressor 13 for servicing or replacement thereof. For example, if the compressor 13 requires servicing, it is possible to almost completely evacuate the compressor, by closing the valve 26 and then operating the system on the cooling cycle for a short peric Then, upon closing the valve 24, almost all of the refrigerant in the system is trapped in the outdoor coils 6, indoor coils 4 and associated tubing. The ends of the refrigerant lines 15 and 18 are sealed against refrigerant loss. Couplings 35 and 36 are then loosened and removed from their fittings on the compressor andheating unit.

switch-over valve without substantial loss ofthe refrigerant charge in the system. Only that charge which is left in the compressor will be lost, which is a fraction of the total refrigerant in the system, and, in large ca'pacity systems, this will result in a substantial savings. After servicing or installation of a new compressor or a new switch-over valve, evacuation can be accomplished after tightening all of the couplings 27, 28, 35 and 36, through service fittings 37 on the valves 24 and 26. A servicemans charging valve or servicing valve of the type well known in the art may be attached to the service fitting 37 and the valve member 38 backed off from the fitting port 39, in the manner well known in the art, and a refrigerant charge may be added to the compressor after it has been suitably purged.

In addition to the above service operations on the compressor and reversing valve, it is sometimes desirable to provide for similar service operations on other refrigerant-carrying components of the system such as the refrigerant filter-drier 20 located in the bypass line 9. Such service operations are provided for with the service valve arrangement described above. For example, should it be necessary to replace the refrigerant filter-drier 20, a serviceman may close the liquid line service valve 41 and set the reversing valve 17 to operate the system as a He then operates the compressor for a sufficient period of time to extract the refrigerant from the outdoor heat exchanger 6 and suction portions of the compressor 13. In so doing, the refrigerant is compressed and delivered into the indoor heat exchanger 4 and refrigerant lines adjacent thereto. The compressor is then stopped and valve 24 is closed. This pump down procedure has now left the outdoor coil 6 the filter-drier 20 and the adjacent refrigerant lines relatively free of refrigerant. Refrigerant lines adjacent to the filter-drier 20, can then be opened and the contaminated filter-drier can be removed and a new one installed. If desirable the filter-drier 20 may be coupled into the system with detachable couplers like the couplers 35 and 36 so that it may be easily removed from the system. The outdoor portions of the refrigerant circuit can then be evacuated or purged; valves 24 and 41, opened and the refrigeration system returned to normal operation. Similar service operations may be performed on the refrigerant-carrying components of the indoor heat exchange and air-handling unit. The only difference being that the indoor portions of the refrigerant system are pumped down" into the outdoor sections by operating the compressor with the reversing valve in the normal cooling position and with liquid line service valve 41 closed.

While there has been described what at present is considered to be the preferred embodiment of the invention, it will be apparent to one skilled in the art that some changes and modifications may be made therein without departing from the invention and it is, therefore, the aim of the appended claims to cover all such changes and modifications as fall within the true spirit and scope of the invention.

What I claim as new and desire to secure by Letters Patent of the United States is:

1. A reversible cycle refrigerating apparatus comprising a compressor, a first heat exchanger and a second heat exchanger, a refrigerant line connecting said first and second heat exchangers, said refrigerant line including refrigerant expansion means adapted to expand refrigerant flowing between said heat exchangers from condenser pressure to evaporator pressure during flow of refrigerant through said line in either direction, a reversing valve, a refrigerant suction tube and a refrigerant dis charge tube connecting said reversing valve with said compressor, refrigerant lines leading respectively to said first heat exchanger and said second heat exchanger from said reversing valve, and service valves detachably connecting said reversing valve to said refrigerant lines leading respectively to said first and second heat exchangers, said service valves having manually operable valve means for closing said refrigerant lines leading to said first and second heat exchangers so that said reversing valve and said compressor may be removed from said system for servicing thereof without losing refrigerant in said first and second heat exchangers and said refrigerant lines associated therewith.

2. A reversible cycle refrigerating apparatus comprising a compressor, a first heat exchanger and a second heat exchanger, a refrigerant line connecting said first and second heat exchangers, said refrigerant line including refrigerant expansion means adapted to expand refrigerant flowing between said heat exchangers from condenser pressure to evaporator pressure during flow of refrigerant through said line in either direction, a reversing valve, a refrigerant suction tube and a refrigerant discharge tube connecting said compressor and said reversing valve, refrigerant lines leading respectively from said reversing valve to said first and second heat exchangers, said refrigerant lines having service valves attached to said ends thereof adjacent said reversing valve, and detachable couplings connecting said service valve to said reversing valve whereby said service valves may be removed from said reversing valve, said service valves including manually operable valve means for closing said refrigerant lines leading from said first and second heat exchangers so that said compressor and said reversing valve may be removed from said system for servicing thereof without loss of refrigerant charge in said heat exchangers.

3. A reversible cycle refrigerating apparatus comprising a compressor, a first heat exchanger and a second heat exchanger, a refrigerant line connecting between said first and second heat exchangers, said refrigerant line including refrigerant expansion means adapted to expand refrigerant flowing between said heat exchangers from condenser pressure to evaporator pressure during flow of refrigerant through said line in either direction, compressor having a gas discharge outlet and a gas suction inlet, a reversing valve, a gas discharge tube and a gas suction tube connecting with said reversing valve, detachable couplings connecting said suction tube and said discharge tube respectively with said discharge outlet and said suction inlet of said compressor, refrigerant lines leading respectively from said reversing valve to said first and second heat exchangers, service valves connected to said refrigerant lines on the ends thereof adjacent said reversing valve, detachable couplings connecting said service valves to said reversing valve, and manually operable valve means in said service valves for closing said refrigerant lines leading to said first and second heat exchangers so that either said reversing valve or said compressor may be removed from said system for servicing thereof without loss of refrigerant charge in said heat exchangers.

References Cited in the file of this patent UNITED STATES PATENTS 

